# Proto Structure Optimization

## Overview

This document describes the optimization of the protobuf structure in the spear-next project, specifically the refactoring from SMS-centric naming to a more accurate node-centric naming convention.

## Background

The original protobuf structure used SMS (Short Message Service) terminology throughout the codebase, which was misleading as the system actually manages compute nodes and tasks, not SMS messages. This naming convention caused confusion and made the codebase harder to understand.

## Changes Made

### 1. Service Renaming

- **SmsService** → **NodeService**
  - The main gRPC service now accurately reflects its purpose of managing compute nodes
  - All client and server implementations updated accordingly

### 2. Proto File Structure

The proto files remain in the `proto/sms/` directory for backward compatibility, but the service definitions have been updated:

- `node.proto`: Contains node management definitions (formerly in sms.proto)
- `task.proto`: Contains task management definitions (unchanged)

### 3. Code Updates

#### Service Layer
- `SmsServiceImpl` → Handles node operations (name kept for compatibility)
- Updated all gRPC method implementations to use NodeService traits

#### HTTP Gateway
- `GatewayState.sms_client` → `GatewayState.node_client`
- Updated all HTTP handlers to use the new client field name

#### Binary and Main
- Updated server initialization to use `NodeServiceServer`
- Updated client connections to use `NodeServiceClient`

#### Tests
- All integration tests updated to use new service names
- Test utilities updated for consistency

### 4. Import Updates

All imports across the codebase have been updated:
```rust
// Before
use spear_next::proto::sms::sms_service_client::SmsServiceClient;
use spear_next::proto::sms::sms_service_server::SmsServiceServer;

// After
use spear_next::proto::sms::node_service_client::NodeServiceClient;
use spear_next::proto::sms::node_service_server::NodeServiceServer;
```

## Benefits

1. **Clarity**: The naming now accurately reflects the system's purpose
2. **Maintainability**: Easier for new developers to understand the codebase
3. **Consistency**: Aligns terminology with actual functionality
4. **Documentation**: Self-documenting code through proper naming

## Backward Compatibility

- Proto package name remains `sms` to avoid breaking existing deployments
- Directory structure preserved for compatibility
- Service implementation class names kept where possible

## Future Considerations

1. **Common Proto**: Evaluated the need for a `common.proto` file but found no shared types requiring extraction
2. **Directory Renaming**: Consider renaming `proto/sms/` to `proto/node/` in a future major version
3. **Package Renaming**: Consider updating the proto package name in a future breaking change

## Testing

All tests pass after the refactoring:
- Integration tests: ✅
- HTTP integration tests: ✅
- Task integration tests: ✅
- KV storage tests: ✅

## Files Modified

### Core Implementation
- `src/services/node.rs`
- `src/http/gateway.rs`
- `src/http/handlers/node.rs`
- `src/http/handlers/resource.rs`
- `src/bin/sms/main.rs`

### Tests
- `tests/integration_tests.rs`
- `tests/http_integration_tests.rs`
- `tests/task_integration_tests.rs`

### Proto
- `proto/sms/node.proto` (service definitions updated)

This refactoring improves code clarity while maintaining full backward compatibility and functionality.